1,720,996 research outputs found
Energy efficiency as option for improving sustainability of agrofood system
No full textAgrofood system embraces two closely related components: direct crop production (agriculture) and food industry which includes processing, retailing and products distribution. FAO reports that the agrofood system is one of the world's largest user of fossil energy, with around 20% of the total energy consumption in developed countries, and a 22% of total annual emissions, with the agriculture component as responsible of around 14% of total global GHG emissions. Agrofood system accounts for 17 % of the EU’s gross energy consumption in 2013, equivalent to about 26 % of the EU’s final energy consumption, producing approximately 11% of the EU agrofood GHG emissions. This paper focuses on the opportunities linked with the application of energy management measures complying with the EU 2012 Energy Efficiency Directive (EED), and with the target of the EC to reduce 20% of GHG by 2020
Environmental impact reduction in greenhouses heating: Biomass-fired absorption heat pump coupled with wood biomass boiler
No full textThis paper deals with an interesting application of different technologies to greenhouse heating systems. First, biomass boilers is a mature and affordable technology, showing high efficiency and long lasting devices. As wood biomass is considered as GHG neutral when converted to heat, it is logical to think about its application to greenhouse heating. Second, the thermally activated heat pumps, and more specifically the absorption heat pump, has reached a mature technology, as well. If the thermally activated heat pumps are coupled with short and long term heat storage, this can enhance the overall efficiency of the system. As greenhouse radiant, floor and bench heating systems can exploit low grade thermal energy, and these interconnections generate virtuous circles for the environmental impact reduction related to greenhouse heating systems
Life cycle impact of industrial aquaculture systems: A review
No full textThe capture fishery production has overexploited the wild-fish stocks and global demand for aquatic products is still increasing. Industrial aquaculture systems, such as marine net-pen, have a life cycle (LC) impact most of which is due to the energy needed to produce feed, and to the marine biotic resource overexploitation. To this regard, it should be worth calculating the primary production required (PPR) indicator to account for the impact of these production systems. Following the PPR approach, a three times higher value could be estimated respect to the life cycle assessment (LCA) method that underestimates the marine biotic impacts of fishery products. LCA is often referred to as â cradle to graveâ analysis. On the contrary, the system boundaries of LCA of aquaculture systems studies are â from cradle to farm-gateâ , thus avoiding the analysis of the subsequent processing, wholesaling, retailing, preparation and disposal of the fish. Anyhow, among the aquaculture systems, conventional marine net-pen has the lowest impact, while typical land-based freshwater recirculating system has a much higher impact, due to a large use of materials and energy, at least an order of magnitude higher than those of the net-pen. Nonetheless, the life cycle environmental impacts of a land-based freshwater recirculating system are very sensitive to the primary energy mix used to generate electricity
L'ottenimento dei Certificati Bianchi. La scheda 40E: i sistemi serra ai sensi del Decreto del Ministero Sviluppo Economico 28.12.2012, art. 15 comma 2
No full textUna Guida Operativa per gli operatori del mondo agricolo con le informazioni di base per la presentazione di progetti standard sulla scheda tecnica 40E per gli incentivi previsti dal DM del 2012 sui Certificati Bianchi. La Guida Operativa riporta la descrizione dei sistemi principali di climatizzazione microclimatica delle serre e dei processi fondamentali che regolano la fisiologia vegetale delle piante allevate in serra. I dati e le informazioni scientifiche riportati sono utili anche per sviluppare eventuali interventi mirati all’introduzione di innovazione tecnologica nei sistemi serra con progetti che ricadano nel sistema di valutazione a consuntivo (PPPM - Proposta di Progetto e Programma di Misura). Infine, nella Guida Operativa sono riportati una serie di chiarimenti tecnici raccolti con l’attività di consulenza svolta dall’ENEA sul sito www.efficienzaenergetica.enea.it e presso il Centro Ricerche Casaccia, per fornire agli operatori le informazioni di base per ottenere i Titoli di Efficienza Energetica con la scheda tecnica 40E
Efficienza energetica e fonti rinnovabili per l’agricoltura protetta
No full textIntroduzione
Il comparto dell’agricoltura protetta (serre in vetro, serre in plastica, tunnel e tunnellini) si
trova oggi a operare in un un mercato internazionale caratterizzato da una costante evoluzione
rispetto sia alla richiesta dei consumatori per le garanzie di “food safety” e sia alla necessità
di ridurre i costi energetici per la climatizzazione delle serre. Pertanto, l’impiego da parte
delle aziende agricole di modelli produttivi caratterizzati da un lato dalla più ampia diversificazione di prodotti vegetali e dall’altro lato da una maggiore efficienza energetica insieme all’applicazione
di tecnologie di climatizzazione che utilizzano energie rinnovabili risultano
ormai fondamentali per rispondere efficacemente alla competizione globale. Le conseguenze di questa situazione si manifestano a diversi livelli della filiera agro-alimentare con prospettive e obiettivi molteplici, tra i quali i principali sono: la valorizzazione di processi produttivi
eco-compatibili, la scelta della sostenibilità energetica ed ambientale come elemento chiave di
competitività, la coerenza con le policy Europee inerenti l’energia, l’efficienza energetica, l’ambiente e lo sviluppo economico sostenibile
Environmental impact of Green roofing: the contribute of a green roof to the sustainable use of natural resources in a life cycle approach
Full text linkEven if several studies and researches have demonstrated that green roofs significantly contribute to energy saving, indoor thermal comfort, urban heat island mitigation, rain-water management and air pollution reduction, environmental benefits of green roofs mainly depend on use of primary energy, natural resources or raw materials used in the construction. A green roof is usually a more or less complex aggregation of different layer addressing each one to a specific characteristic and performance. Results of previous LCA researches, based on a cold climate scenario, have demonstrated the highest influence that some specific layers have on the overall impact of the green roofs and to what extent the global impact changes when insulation and the substrate layers vary in density and quality. Starting from results of these similar EU researches, this study aims to evaluate the variation of the overall impact in hot climates where insulation is less strategic than heat capacity. LCA has been applied to assess and compare the environmental impacts of four different green roof solutions compared to a standard clay pitched roof, based on the functional unit of 1m2 with the same reference service life, where layers have been selected according to local practice and market. Despite a general equivalence in environmental impacts of all the roofing elements, results have highlighted a general lack in specific life cycle inventory information that leads to a potential inaccuracy of the assessment especially when recycled material are used in the growing medium or when disposal scenario includes recycle processes
Simulation of the thermal behaviour of a building retrofitted with a green roof: optimization of energy efficiency with reference to italian climatic zones
Full text linkRunning a building energy simulation program (EnergyPlus), simulations were conducted on a 'public housing' building type, in
order to evaluate the energy savings achieved by a green roof coupled with different configurations of external wall. EnergyPlus
enabled the investigation of the thermal behaviour variations of the building envelope, and the possible consequences, in terms of
comfort, on the temperature of the internal spaces. The variation of the energy behaviour of the building envelope type was
assessed primarily through the analysis of the operative temperature T° of the elements of surface casing, the trend of the surface
heat fluxes on the faces of the elements of internal and external housing, the variation of the operating temperature inside the
rooms. The energy savings achieved with a green roof varies considerably in relation to the reference performance obtained
without this kind of insulating structure. The main parameters, useful to define the contribution of the green roof to the reduction
of the loads of cooling plants, consist of the specific climate and the thermal isolation level of the initial coverage
LCA environmental parameters of green roofs: a comparison of results and an overview on data quality
No full textThis paper presents the environmental performance of six greenroof solutions currently available on the Italian market and highlight the lack of information, both environmental and thermal, that are necessary to run a complete and specific assessment. The paper also aims to demonstrate how LCA could support producers in designing more efficient and low impact greenroofs, selecting materials based on their environmental profile over their life cycle and taking into account potential reuse of recycle at the end of life
Toward a dynamically configurable and upgradable greenhouse environment simulation PC platform
No full textA computing platform is the environment in which a piece of software is executed. It may be the operating system (OS) or other application, as long as the code is executed in it. Platforms may also include software frameworks that provide ready-made functionality. During the past decades, several greenhouse environment simulation and climate control models have been investigated. Regardless the type, the development of a good predictive model is compulsory to achieve adequate control performances. In order to provide a flexible interactive tool, the Xnumbers Excel® addin by L. Volpi, along with the Visual Basic for Applications (VBA), allowed to customize a workbook to fit the simulation of the greenhouse environment. Within this extent, the first workbook of the dynamically configurable and upgradable platform for the simulation of a greenhouse environment has been provided. The paper presents the relationship among Xnumbers Excel® addin , VBA code and the Excel workbook threads within the application developed in MS Excel Environment
Performance Evaluation of a Solar Cooling Plant Applied for Greenhouse Thermal Control
No full textThe greenhouses cultivation causes in summer season inner conditions characterized by high thermal levels such as to generate problems that can damage crops. Always more frequently for this reason it is common to provide greenhouse with air conditioning plants. In this work it will be presented an application of a solar cooling plant with absorption cooling machine for thermal control of a greenhouse and an advanced simulation model able to evaluate optimal plant configurations and controls. Solar cooling systems can be applied for greenhouse climate control in regions with high values of solar irradiation as alternative to traditional evaporative systems, allowing the reduction of primary energy consumption by exploiting the contemporaneity between the cooling requirements and the solar energy availability.
The plant consists of a single effect LiBr-H2O absorption chiller fed by evacuated-tube solar collectors; the model was developed in Matlab-Simulink and is able to simulate dynamically, with time steps up to 15 minutes, the greenhouse cooling demand and the production of the solar field.
Present study proposes a plant configuration with a distribution system in which the cooling power is not provided for the entire volume of the greenhouse, but only for the air volume surrounding the crop with a considerable saving of reduction of energy demand and an extremely efficient use of solar energy. The simulation study is based on the experimental data collected at the experimental center of the University of Bari, Southern Italy.
The aim of the work is to demonstrate that solar cooling system could provide significant energy-saving opportunities for cooling greenhouses allowing the reduction of primary energy consumption by exploiting the contemporaneity between the cooling requirements and the solar energy availability
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